1. Field of the Invention
The present invention relates to an electronic circuit module, and more particularly, to an electronic circuit module that can be appropriately used for a module having a chip with bumps mounted to a multi-layer wiring plate in a flip chip manner.
2. Description of the Related Art
FIG. 5 is a diagram illustrating an electronic circuit module 101 according to the related art. As shown in FIG. 5, the electronic circuit module 101 according to the related art is formed by mounting a semiconductor chip 102 to the front surface of a multi-layer wiring plate 104 in a flip chip manner. The multi-layer wiring plate 104 is formed in a laminated structure of wiring plates 105 obtained by providing surface electrodes 107, internal electrodes 108 and external connection electrodes 109 on the front and rear surfaces of a plurality of ceramic substrates (LTCC and HTCC) 106.
However, as shown in FIG. 5, when the internal electrodes 108 are concentrated inside the multi-layer wiring plate 104 below the chip 102 in order to improve the degree of the integration of the multi-layer wiring plate 104, the front surface of the multi-layer wiring plate 104 partially protrudes to come into contact with the chip 102 due to an increase in the thickness of the electrodes 108 overlapping each other, which makes it difficult to connect bumps 103 of the chip 102 to surface electrodes 107 of the multi-layer wiring plate 104.
Further, as shown in FIGS. 6 and 7, when the surface electrode 107 have a non-uniform thickness due to the arrangement of the internal electrodes 108, the chip 102 is mounted to the multi-layer wiring plate 104 in a flip chip manner while some of the bumps 103, that is, bumps 103A do not come into contact with the surface electrodes 107, which causes bad connection between the chip 102 and the multi-layer wiring plate 104, resulting in low connection reliability of the chip 102.